Cat mapping

By Tim Hyland

A group of leading veterinary and genetic researchers from around the country recently announced that they had sequenced the genome of … a domestic cat.

And though there are myriad reasons—some related to animal health, some to human health—why this massive project was undertaken in the first place, Penn’s Urs Giger says one stands out above the rest: People love their pets.

“Dogs and cats have been improving their status in the family over the past few decades,” says Giger, section chief of Medical Genetics at Penn’s School of Veterinary Medicine. “It’s to the point now where the dog is man’s best friend and the cat may be the second best friend. As such, these animals have received more medical attention.”

The sequencing, or “mapping,” of the cat genome—announced last month in an article in the journal Genome Research—only figures to advance the health of our feline and canine friends (the canine genome was released in 2005) even further, says Giger. It’s just a nice bonus that humans may benefit, too.

Working under the guidance of the National Institutes of Health, researchers on this project first mapped the DNA of a 4-year-old Abyssinian cat named Cinnamon using a method called light genome sequence coverage, the same method that is also being used to sequence the DNA of several other mammals. Later, a group of scientists, Giger included, were called together to help make sense of Cinnamon’s genetic map.

By sorting through this raw DNA data, researchers may be able to glean more information than ever before about the genetic makeup of felines. In the process, they may also be able to develop new treatments for any number of genetic diseases, both in cats and humans.

“The advances at the molecular level will certainly improve the health of these animals, not just in treating them, but also in regard to the prevention of disease that spread with breeding,” explains Giger, who has spent much of his career searching for cures to genetic disease.

The domestic cat suffers from more than 200 known hereditary diseases, and some of those, researchers say, aren’t all that dissimilar to the genetic diseases suffered by humans.

“The shift [in veterinary medicine] has been about getting more and more work done with genetic disorders,” Giger says. “While in 1950 we maybe only knew a handful of hereditary diseases in dogs and cats, nowadays we know of hundreds. But these diseases are not only problematic for particular cat or dog breeds. They represent important models of human diseases, too.”

Already, Cinnamon’s genomic information has proved useful: Using the sequence data, the research team identified several hundred thousand genomic variants that can be used to determine the genetic basis for common hereditary diseases. One of those variants, the team has announced, was the genetic mutation that caused Cinnamon’s retinitis pigmentosa, a degenerative eye disease that can cause blindness.

This discovery offers a small example of how powerful this information is. That’s because retinitis pigmentosa doesn’t only affect cats—it also is a problem for humans, affecting 1 in 3,500 Americans. And now, thanks to Cinnamon, scientists have a clearer picture than ever before of how and why this disease develops.

But that’s just the tip of the iceburg.

According to the research team, the genetic information gleaned from Cinnamon’s genome could also hold valuables clues to the development of any number of infectious diseases—including HIV/AIDS.

Penn Current Express

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